Abstract We propose single-cell technologies to quantify multiparameter immune markers that provide in- depth single-cell data for analysis of immune responses to vaccination in our study cohorts. The shared platforms in this service core provide efficient and reproducible profiling in support of our research projects with greatly expanded sensitivity and cell-type specificity. To define cell phenotypes, we will employ mass cytometry or CyTOF (Cytometry by Time-Of-Flight) for multiparameter single-cell analysis, which uses heavy metal ions as antibody labels and provides tremendous detail for cellular analysis of immune subsets. To further profile and correlate the transcriptomes of targeted single cells with immunophenotype, we will employ single-cell cellular indexing of transcriptomes and epitopes by sequencing (CITE-Seq) for circulating blood cells and spatial-resolution proteo-transcriptomics via deterministic barcoding (DBiT-seq) in biopsies from tissues (skin, lymph node). These transcriptomics include in depth sequencing of BCR and TCR to investigate clonal expansion in the tissue compared to the circulation. To identify molecular signatures of vaccine responses across our cohorts, we will use a mass spectrometry (MS)-based MStern blotting-based serum proteomics platform for unbiased discovery of several hundred proteins with immunological function as an excellent reflection of the immunological state. Standardization, both at the assay and analytical levels, will allow comparisons and integration of data across projects. The goals of Core C are to provide a unique and essential resource to enable the comprehensive characterization of circulating immune cells from blood as well as cells available from tissue biopsies, with comparative data by CyTOF and RNA-sequencing (RNA-seq), and matched profiles of proteomic milieu.